The effects of negative and positive pressure breathing on plasma renin concentration (PRC) and urine volume (UV) have been studied in dogs.
Negative pressure breathing in intact dogs caused an increase in UV and a decrease in PRC, whereas, during positive pressure breathing, UV fell and PRC rose. The changes were reversed by breathing at atmospheric pressure.
In dogs with one autotransplanted kidney, basal PRC was much lower than in controls. In contrast to the latter, the former showed no significant change in PRC under negative pressure breathing, whereas, during positive pressure breathing, PRC increased. Changes in breathing pressure affected UV similarly in controls and in dogs with an autotransplanted kidney.
The results obtained do not permit conclusions as to the significance of kidney innervation for the regulation of renin release. Reduction of renal mass in dogs with one autotransplanted kidney may influence the activity of the renin-angiotensin system and consequently its response to changes in breathing pressure. Since changes in UV induced by positive or negative pressure breathing are similar in dogs with two innervated and in dogs with one autotransplanted kidney, renin release may be of only minor significance for variations in antidiuretic hormone secretion under these conditions.